Super Jet superjet cutting out at 3/4- full throttle. ?

[yurkanip]

Specs: stock superjet 650 rebuilt top end. Stock carb, stock intake, stock exhaust. Only think aftermarket is a aftermarket head ~180psi. and hooker 9/15 prop.

Motor ran very strong up until this weekend, and is going to be swapped for a 701 over winter. I have a few months of riding left here, and want to get this motor back to pulling strong.
After one firehose and a sub, the motor clearly had water in the fuel and it hesitated. I drained the fuel, etc. seemed to be fine with new fuel. Started doing it again, so I drained the tank/water seperator and removed the stock fuel filter which was full of what looked like paint flakes, no joke. replaced with a brand new, Napa inline fuel filter because it was all I had while camping.
new fuel, motor runs better but is still cutting out and stalling at 3/4-full throttle. I let off the throttle, it will idle and pull under power again for maybe 50 yards then cuts and I slam mychest into the bars. repeat, repeat.
This motor has been super strong for years, and just started doing this after a sub, and fire hose.

Possible that getting water in the fuel, knocked some debris loose and is now in the carbs? OR is this a highspeed setting that was possible tweaked somehow??
any carb gurus?

I am using the stock, gastank check valve and it seems to work fine, but I have not replaced that FYI.

Thoughts and feedback.

Thanks
Patrick

 

[tipafew]

You can just remove the check valve for a test ride.

I would vote the fuel screen inside the carb. On the fuel pump side there is a cylinder shaped screen that will get plugged up.

 

[Idok]

I agree on the carb screen....

 

[tor*p*do]

or water in the carb
either way it needs to be stripped down, cleaned and rebuilt

 

[yurkanip]

Thanks guys. I had a few things going on. I think I'm getting closer. There was some water in the fuel. As well as the stock filter stuffed back under the rear lip of the ski was almost full of debris. Literally looked like paint chips floating Around in there. Replaced with a much larger fuel filter and ran sea foam through. It is mostly flushed out. Not even going to bother rebuilding carb as I'm upgrading to a 718 with single 46 this winter in my bob build. Just needed to have it running for the last family ride this weekend / labor day.